The invention relates to drilling machines, and more particularly, to drilling machines having a rotary head guide.
Drilling machines typically include a frame, a tower, and a rotary head. The frame is supported for movement over the ground, and the tower is mounted on the frame. The tower defines a longitudinal axis and includes an elongated member, or chord, that extends parallel to the longitudinal axis. The rotary head is engageable with the drill string for rotating the drill string.
The rotary head includes rotary head guides that are connected to opposite sides of the rotary head and that engage the elongated members to allow the rotary head to move upward and downward along the elongated members. The rotary head guides engage the elongated members with engaging members such as rollers, rack and pinion drives, and wear blocks.
The rotary head connects with the drill string, rotates the drill string, and forces the drill string downward to penetrate the ground and create a drilled hole. Drilling operations transfer upward forces against the rotary head and torque forces that tend to rotate the rotary head outward, away from the elongated members. The rotary head guides resist the rotation of the rotary head caused by the torque created from drilling operations to maintain the alignment of the rotary head with the tower and elongated members.
These known systems are disadvantageous because they cannot compensate for excessive wear resulting in large gaps between the rotary head guide and the elongated members. Gaps between the rotary head guides and the elongated members allow misalignment of the rotary head, and, in turn, misalignment of the drill rods when attempting to connect drill rods to create a drill string. In addition, it is inconvenient to replace and maintain the engaging members of the rotary head guides because a crane is required to support the rotary head during the repair of the engaging members.
The rotary head guide of the present invention improves the alignment of the rotary head by allowing an operator to eliminate gaps and maintain proper spacing between the wear plates and the elongated members. The rotary head guide also improves the alignment of the rotary head by increasing the rotary head guide contact length with the elongated member to a length that is greater than the distance between the elongated members. The present invention also eliminates the need for shim sets by providing adjustment mechanisms that move the wear plates against the elongated members to eliminate large gaps due to operation wear between the wear plates and the elongated members. Further, the rotary head guide eliminates the need for a crane to support the rotary head during maintenance by providing a second set of engaging members connected to each of the supports so that one set of engaging members can be replaced or adjusted while the second set of engaging members support the rotary head by coupling to the elongated members.
One embodiment of the present invention is directed to a drilling machine for use with a drill string. The drilling machine includes a rotary head guide that is slidably coupled to an elongated member for movement along a tower. The rotary head guide includes a support, a wear block, a backing bar, and an adjustment mechanism. The support is coupled to a rotary head, the wear block is slidably engaged with the elongated member, and the backing bar is coupled between the wear block and the support. The adjustment mechanism is coupled to the support and engages the backing bar such that adjustment of the adjustment mechanism moves the backing bar away from the support to move the wear block against the elongated member.
Another embodiment of the present invention is directed to a drilling machine for use with a drill string. The drilling machine includes a rotary head guide that is slidably coupled to an elongated member for movement along a tower. The rotary head guide includes a support and first and second wear block assemblies. The support is coupled to a rotary head, and the first and second wear block assemblies are coupled to the support and engageable with the elongated member. The first and second wear block assemblies are positioned in an end to end relationship in the direction of a longitudinal axis of a tower such that one of either the first and second wear block assemblies can be adjusted to engage the elongated member and support the rotary head to allow maintenance to be performed on the other wear block assembly.
An additional embodiment of the present invention is directed to a drilling machine for use with a drill string. The drilling machine includes a first rotary head guide that is coupled to a first side of a rotary head and a second rotary head guide that is coupled to the other side of the rotary head. The first rotary head guide has a first length parallel to a longitudinal axis of a tower and is slidably engaged with a first elongated member and the second rotary head guide has a second length parallel to the longitudinal axis and is slidably engaged with a second elongated member. The lengths of the rotary head guides each being greater than the distance between the elongated members.
Another embodiment of the present invention is directed to a method for providing maintenance to a drilling machine for use with a drill string. The method includes providing a rotary head guide slidably coupled to an elongated member for movement along a tower, the rotary head guide including a support coupled to a rotary head, and first and second wear block assemblies coupled to the support and engageable with the elongated member, wherein the first and second wear block assemblies are positioned in an end to end relationship in the direction of a longitudinal axis of the tower, and supporting the rotary head with one of the first and second wear block assemblies to allow maintenance to be performed on the other wear block assembly.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.